FWIW I had a very bad reaction a couple of days ago from the excessive flashing/strobing, first time in over 30+ years of gaming.
I had severe nausea, dizziness and eyeballs went haywire; it knocked me on my arse for the rest of the day and some of the next morning.
I think it was mostly due to the power sword strobing in dark areas and made worse by psyker spell effects. I’ve seen others mention the power sword in discord mod requests to dampen the visual FX for it. Additionally I think it may be further exacerbated by using HDR (OLED) and properly calibrated brightness/contrast.
I had a smaller bout today as well, and just now on testing; it’s a very unpleasant experience and muted effects and elimination of strobing would be most welcome.